I am sorry for all your losses :( I just borrowed the book, Pregnancy After A Loss by Carol Cirulli Lanham and it talked about doing tests for autoimmune disorders and also suggested different tests for different miscarriage and stillbirth reasons. You might find it useful. Unfortunately, I checked out the only copy available. You could also buy a copy off Amazon.com.

Millyhk, I didn't have my tests done in HK, but in Europe before I came here. It took me 6 months as they were pushing the tests to the end, not finding anything to the first ones. It appeared it was a coagulation problem.
When I came here I went to see Dr Christine Choy, and she took it very seriously. She gave me some treatments and since then I got 2 children !

Sorry I didn't get back to you earlier. I used Dr Alex Doo at the Women's Clinic. My first successful IVF :)
You cann find his details on the directory. Dr Ho is also very good. I liked that dr Doo had very up to date approach and was willing to try different treatments etc.
I found dr Choi extremaly overpriced especially when it came to drugs. I didn't use her for fertility treatment just for a pap etc.She tried to convince me to go with her for IVF but I didn't like here prices and pushy approach. But this is just my personal impression and I'm sure she is ok as a doctor.